Experimental research of novel aluminium-ammonia heat pipes

Abstract The axial heat pipe with Ω-shaped grooves can not only increase the permeability for liquid, but also reduce the flow resistance between the vapor and water greatly. In this paper the thermal characteristics of aluminum-ammonia heat pipes with Ω-shaped grooves were investigated. The conclusion is that the heat pipe has a good ability of dynamic response. With the same operating temperature, the differences between evaporation section and condensation section increase with increasing the input power. The maximum and minimum temperatures of the heat pipes are respectively at the end of the heating section and the beginning of the condensing section. The equivalent thermal conductivity of the heat pipe increases with the increase of the operating temperature, and increases with the increase of input power and liquid filling rate. The total thermal resistance of the heat pipe decreases with the increase of input power, and the heat resistance is the smallest when the angle of heat pipe is 60°. With the increase of the liquid filling rate, the maximum heat transfer capacity of the heat pipe increases, but the amplitude is getting smaller and smaller.